• Journal of The Korean Society of Grassland and Forage Science
• /
• v.24 no.1
• /
• pp.29-36
• /
• 2004

In an effort to optimize tissue culture responses of zoysiagrass(Zoysia japonica Steud.) for genetic transformation, factors affecting callus induction and plant regeneration were investigated. MS medium containing 3 mg/L 2,4-D was optimal for embryogenic callus induction from mature seed. The plant regeneration frequency of 73.3% was observed when embryogenic calli induced in this medium were transferred to N6 medium supplemented with 0.1 mg/L 2,4-D and 5 mg/L BA. Among several basic media, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. Regenerated plants were grown normally when shoots transplanted to the soil. A rapid and efficient plant regeneration system established in this study will be useful for molecular breeding of turfgrass through genetic transformation.

• Journal of Plant Biotechnology
• /
• v.36 no.1
• /
• pp.18-22
• /
• 2009

This work was conducted to establish an efficient plant regeneration system for genetic transformation and the in vitro conservation of Sedum sarmentosum genetic resources. Effects of glutamine and $AgNO_3$ on plant regeneration between two genotypes were investigated using MS media supplemented with 0.2 mg/L NM and 3.0 mg/L BA. Calluses were formed on leaf explants placed on MS solid media supplemented with 3 mg/L 2,4-D and 1 mg/L BA. Calluses of Keumsan local strain produced shoots at a frequency of up to 100% after 50 days of culture on medium supplemented with glutamine. The highest number of shoots per callus was 17.6 at 350 mg/L glutamine. However, calluses of Wanju local strain gave rise to no shoots under the same culture conditions. Likewise, calluses of Keumsan local strain produced shoots at a frequency of up to 100% after 50 days of culture on medium supplemented with $AgNO_3$ whereas Wanju local strain sporadically produced shoots. The highest number of shoots per callus of Keumsan local stain was 16.1 at $15{\mu}M$ $AgNO_3$. Regenerated shoots were subcultured on hormone-free MS medium for rooting and shoot growth, and then 3-5 cm high plantlets were transplanted to the artificial soils comprising vermiculite and perlite, where they survived at a frequency of 88-100%. After being transplanted into upland soil:sand (1:1, v/v) in a greenhouse, regenerated plants showed a morphologically normal growth.

• Journal of Life Science
• /
• v.17 no.7 s.87
• /
• pp.976-982
• /
• 2007

The purpose of this study was to determine the modulating effects of histone deacetylase inhibitor, trichostatin A, on the differentiation of mouse C2C12 myoblasts. We demonstrated that trichostatin A induced morphological changes of C2C12 myoblasts into smooth muscles and significantly increased the gene expression of smooth muscle markers including smooth muscle ${\alpha}-actin$ and transgelin. These results were due to the change in the expression level of cell cycle regulators in trichostatin A-treated C2C12 cells. Real-time PCR data revealed that cyclin dependent kinase inhibitor, p21, mRNA expression was significantly increased in trichostatin A-treated C2C12 cells. However, trichostaDn A rapidly decreased cyclin Dl mRNA expression necessary for cell cycle progression in 24hr after treatment. In conclusion, the strong inhibitory effects of trichostatin A on histone deacetylation induced transdifferentiation of C2C12 myoblasts into smooth muscle cells and these results are partly due to the changes in the expression of cell cycle regulators such as p21 and cyclin D1.

• Journal of Life Science
• /
• v.16 no.2 s.75
• /
• pp.231-239
• /
• 2006

Human mesenchymal stem cells (hMSCs) in bone marrow (BM) can be induced to differentiate into a variety of mesenchymal tissues, including adipocytes, osteoblasts and chondroblasts, under the influence of certain growth or environmental factors. In this study, we analyzed the differentiation process and the associated gene expression profiles inherent to the process by which hMSCs differentiate into osteoblasts. We conducted a comparison of gene expression profiles of the normal human BM MSCs, using human 8K cDNA microarray, incubated in media containing either a combination of $\beta$-glycerol phosphate, L-ascorbic acid, and dexamethasone, or in medium lacking these osteogenic supplements. During the osteoblastic differentiation process, 36 genes were determined to be up-regulated, and 59 genes were shown to be down-regulated. Osteoprotegerin, LRP5, and metallothionein 2A, all of which are associated with the osteogenetic process, were up-regulated, and genes associated with the differentiation of MSCs into other lineages, including muscle, adipose tissue and vascular structure were down-regulated. The set of differentially expressed genes reported in this work should contribute to our current understanding of the processes inherent to the differentiation of MSCs into osteoblasts.

• Journal of the Korean Geographical Society
• /
• v.32 no.1
• /
• pp.47-68
• /
• 1997

The purpose of this study is to clarify both the characteristics of the spatial variations and structure and the logic of spatial differentiation of the renter farming in Korea. The renter farming has transformed its spatial structure from zonal to Thunen's rings-like pattern. This study also suggests that the spatial characteristics of the renter farming has been changed from the ecological and the tenantable to the economical and commercial. Although there is no single logic full explanation the order of such spatial differentiations, the logic of industrialization or neoclassical economics seems to be most effective.

• Proceedings of the Korean Society of Grassland Science Conference
• /
• 2000.09a
• /
• pp.103.1-103
• /
• 2000

• The Korean Journal of Zoology
• /
• v.36 no.3
• /
• pp.342-346
• /
• 1993

The protein level of cytoskeletons in cultured myoblasts was found to gradually decrease during the course of myogenesis. This decrease, however, could be prevented by treatiag the ceils with calpeptin (benzyloxycarbonyl-Leu-nLeu-H), a cell penetrating inhibitor of calpain. In contrast, E-64, which also is a potent inhibitor of calpain but can not be transported into the cells, showed little or no effect. In addition, the treatment of calpeptin was found to stabilize a number of specific cytoskeletal proteins from degradation but without any effect on the pattern of total cells proteins. Furthermore, calpeptin, but not E-64, blocked myoblast fusion in a dose-dependent manner. These results suggest that calpain is responsible for the myogenic time-dependent loss of cytoskeletal proteins and that the degradative process is associated with myoblast fusion. These results also suggest that the differential effects of the calpain inhibitors depend on the permeabIlity of the drugs across the cell membrane.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.3
• /
• pp.197-202
• /
• 2000

The effect of cultural media and growth regulators on multiple plant regeneration from leaf explants of Heloniopsis orientalis (Thunb.) Tanaka was evaluated. The highest percentage of shoot and root formation were 20 and 30% on MS medium treated at 3.0 mg $l^{-1}$ of zeatin, respectively. Also 67 and 33% of high shoot formation appeared on 1/2 MS and 5 culture medium treated at zeatin 1.0 and 3.0 mg $l^{-1}$ respectively. With MS treated at 0.5 mg $l^{-1}$ of 2,4-D 1/2 MS and B5 culture media treated at each 1.0 and 3.0 mg $l^{-1}$ of zeatin the highest ratios of plant produced were 100, 280 and 310 % respectively relative to the other treatments. Generally, there was highest possibility for multiple propagation of Heloniopsis orientalis (Thunb.) C. Tanaka with B5 culture media supplemented 3.0 mg $l^{-1}$ of zeatin.

• Korean Journal of Plant Tissue Culture
• /
• v.26 no.1
• /
• pp.21-26
• /
• 1999

These experiments were attempted to introduce rolC gene in the Petunia hybrida cv. Titan white by Agrobacterium mediated. The maximum frequency of shoot regeneration was obtained by 60% on MS medium containing 1.0 mg/L BA, 0.1 mg/L NAA, 200 mg/L kanamycin, 500 mg/L carbenicillin, 30 g/L sucrose, and 8 g/L agar. Kanamycin-resistant calli were selected from petunia leaf discs by cocultivation with Agrobacterium suspension cultures on MS medium. The addition of AgNO$_3$ and KMnO$_4$ in the medium increased the shoot regeneration by 31.3% from leaf disc as compared with non-treated leaf disc. Among clones exhibiting kanamycin resistance, only 3 clones were confirmed by southern hybridization analysis.

• Korean Journal of Plant Tissue Culture
• /
• v.22 no.2
• /
• pp.83-87
• /
• 1995

Regulation of organ differentiation by growth regulators was investigated through the shoot-tip and bulb-scale cultures of Lilium longiflorum (cv Georgia). When shoot tips were placed on MS medium supplemented with 0.1 mg/L NAA alone or 0.1 mg/L NAA and 0.1 mg/L BA, axillary shoots were proliferated. Root diffentiation and growth were stimulated on the basal medium. Although growth regulation did not seem to be necessary when bulb scales were used as explants for shoot differentiation, its differentiation was promoted vigorously by 0.2 mg/L NAA, but suppressed by BA. Bulblets were formed from bulb-scale-derived plantlets cultured on MS medium supplemented with 0.1 mg/L IBA. And more bulblets were formed from the plantlet in MS medium supplying 0.2 mg/L NAA with 6% than3% sucrose